The present invention relates to an electromagnetic induction chip card including a device for activating and deactivating its RF radio frequency antenna. It finds a particularly interesting application, but not exclusively, in the radio frequency identification (RFID) technology. The invention relates in particular to an NFC type contactless chip card, Mifare, ISO 14443 or 15693, that is an RF antenna transmitting when it is located in a suitable electromagnetic field.
Generally, an RFID card includes one (or more) silicon electronic chips containing more or less sensitive information and relating to the cardholder. This RFID chip is generally connected to an antenna. The RFID card can have the conventional format of a chip card, but can also take different forms such as a badge, a tag, a keychain or other . . . . An integrated battery can be provided so as to extend the card functionalities.
RFID technology, based on the electromagnetic induction principle is increasingly widespread in everyday life. Initially used for managing stocks, this technology has been largely widespread in the access control field. It is rapidly growing in the passport and payment fields. In Japan, for example, it is commonly used as a payment means through the Felica protocol. In USA, the first payment terminals based on the ISO14443A protocol have already being launched. The launch in France is under way nowadays.
Unfortunately, this keen interest in this technology has been made to the detriment of security. The result is that an ill-intentioned person can freely access to information contained in an RFID chip. Given that an RFID chip becomes active in the presence of an electromagnetic field, it is sufficient to manufacture a powerful enough reader capable of recovering information contained in surrounding RFID chips.
Thus, it is possible to recover, without the holder's knowledge, the bank card number or any other personal information contained in a passport for example.
A simple solution is to make the RFID chip active only on the holder's initiative. Thus, the risk to recover data contained in the chip is dramatically reduced. A method is to place a switch at the antenna in order to switch off the communication when the RF exchanges are not necessary. This mechanism can be made in several ways.
Document US 2006/0017570 describes a system enabling the part corresponding to the transponder in an RFID chip or card to be mechanically activated or deactivated. This system relates in particular to cards including a RIFD chip as well as a magnetic tape. The system enables the wireless access to the RFID part to be blocked while allowing the magnetic operation. To block the access, this system proposes a magnetic protection means, a magnetic shield made of a material having a high relative magnetic permeability which is placed in front of or about the antenna so as to avoid any reception of foreign signals.
Document US 2006/0132313 describes a first embodiment wherein the RFID chip is irreversibly destroyed or deactivated by physically detaching the antenna from the rest of the chip. A second embodiment is to dramatically reduce the operating range of the RFID antenna so that any access to the RFID chip should be made very closely, thus to the knowledge of the user. For that purpose, it is in particular provided to reversibly cover at least one part of the antenna with an insulation material sheet so as to dramatically limit the antenna performance.
Document WO 2006/031531 describes a system for activating and deactivating an RFID chip by connecting and disconnecting the antenna. For that purpose, a conducting tape is used which will connect the antenna with the RFID chip or not. This conducting tape can be controlled by a magnet. This document relates in particular to activating or activating an RFID chip from a deactivation device initially intended for an anti-theft tag.
Document EP1918859 describes a scrambling card to prevent a reader from reading data contained in an RFID chip for example. In this system, the RFID chip card is not modified, but a new scrambling card is added, which is intended to emit a signal to scramble reading of data contained in the RFID chip. This second scrambling card can be activated or deactivated by means of a mechanical or electronic switch such as a controlled transistor.
Document WO 2009/100005 describes a system for tuning or detuning the antenna of an RFID chip. This system includes a switch which modifies the antenna impedance such that when the switch is on the ON position, the impedance has a value for which the antenna is tuned and the transmission can occur. On the other hand, when the switch is on the OFF position, the antenna impedance has a value for which the antenna is detuned, which makes the signal transmission impossible.